A face of a person is a main subject of a digital still camera (hereafter referred to as “a camera”) and a digital video camera. Therefore, when photographing, a technology which detects a face of a person and performs automatic focusing control or automatic exposure control suitable for the face of the person was desired:
Further, in actual photographing, in addition to a face of a person who is to be photographed, other faces of persons are also photographed simultaneously. For this reason, a technology which detects and tracks only a specific face among a plurality of faces was also desired.
Patent document 1 discloses a technology which detects and tracks only a registered subject by registering characteristic information about an image of a specific part of the subject such as a face in advance, and by comparing this information and a screen image on a monitor.
Patent document 2 discloses a technology in which a mobile phone extracts a facial image of a person from a motion picture which is being photographed and transmits it to a server; and the server compares it with facial images registered in advance, transmits proper information about a person corresponding to the facial image which agreed in the comparison to the mobile phone and make it displayed.
Patent document 1: Japanese Patent Application Laid-Open No. 2006-101186
Patent document 2: Japanese Patent Application Laid-Open No. 2006-293912
Patent document 3: Japanese Patent Application Laid-Open No. 1993-334411